Step 1: Stuff We Need for This.

I got an old PSU from a computer, had burned it's 5V rail due to some bitcoin miners running from it. First i thought about repairing it, making an ITX powersource or a Bench Power Supply...

But after opening the case, i realized that it was so tightly packed (and dirty from all the dust it sucked through over his lifetime), that it would be to complicated/intense to really fix it and it will probably running to hot anyways in this small case. So, i decided to salvage it's parts an put the remaining residue into the trash (err, giving it to the correct recycling path). There are still a bunch of electrolytic capacitors and other parts which will nicely fit into my bins and boxes.

Step 2: A Simple Trick Using Prototyping Pcbs.

As you can see, i stacked some prototyping pcbs together and put rubber bands around it. I took some care to make sure, no rubber band overlaps with itself or any other to add at least the same height onto the stack.

Then i stuck some male pin headers in it and wrapped a bit of rubber band around to keep it in place.

The simple trick is, now i have a temporary attachment where i can stick the pin headers in to solder them without needing to much additional hands. ;)

I made this not to just only hold my male pin headers while soldering them, but even to keep them all in the same height while they're hot and probably melt through its plastic surrounding stuff.

Those male pins get really fast really hot an the plastic which holds them in place usually cannot withstand it.

That's mostly no problem if you solder a bunch of pins on a PCB, but for this task we may need to keep the heat a bit longer on these pins an they surely will start to move and melt the plastic. This way, stuck into prototyping pcbs, standing directly on the desk or some other surface (i put a small metal box from some mints under it later on), they cannot move in any direction while soldering. Just a nice fast and cheap (and completely reusable) hack.

You may think about using your breadboard for the same purpose, but it will melt too and damage your breadboard easily!

I made several attempts for my "ideal stack", sadly i forgot to make a pic from the "final one" which survived until i soldered all wires i need. But well, i'm sure you get the idea. ;)

Step 3: Cut (salvage) and Solder Some Wires.

As i wrote already, i decided not to really keep to much stuff but simply cut the wires of the PSU. Instead of what i posed in the picture, i opened the case and cut trough the wires as near to the pcb as i could easily reach, just to save at least a centimeter more of the wire.. ;) But, that's not really necessary and you do not need to open the case, you can just cut them like shown on the picture.

Then, as you should now if you have soldering skills. Cut a piece of the insulation from the wire, prepare it and put some solder on it and then, well we can already start to solder our wires.

I grabbed my pin headers and took 2 pins from it and stuck it into the prototyping board, tried to wrap the wires a bit around the pins but realized really fast, that it's nearly impossible without bending the pins.

So, in the long run, i just soldered the wires from the side to the pins, yep both pins!, and go through all wires this way.

You can see the result in the pictures. It will make things a bit more tight on the breadboards but we will make sure that it makes no problem later on...

By the way. I used 2 pins for every single connection between wires an breadboard. Usually you will need just one pin but at low voltages between 1 and 5 volts (most digital stuff today needs anything between 3,3 and 5v), you add more and more loss of voltage with every bit of wire and every connection (and its connection resistance).

So, to make sure, 3.3V inserted on the top of my breadboard setup really comes to the bottom still going 3.3V on the meter, i always use 2 pins for each connection.

(For the "main power source cabling" i even used 3 pins ;) ).

Step 4: Proper Insulation.

As you can see, connecting a bunch of your self build wires onto breadboards might lead to the risk of shorting.

That cannot only kill your PSU or Battery but even make things just unstable and vulnerable to any movement.

To prevent this, i just took a strip of insulating tape, punched my pins from the sticky side through the tape and then fold it over to the top from both sides to insulate the important part.

That not only insulates my wires but nicely marks V+ and Ground connections and even makes a nice little handle to pull them out when needed.... Yeah man. ;)

You can see, all this care even takes a bit of space on the breadboard, but it makes nice, safe and durable connections on the board and you never need to care about that part ever again. ;)

Step 5: Optional Heat Shrink Tubing.

Well, as you can guess, i like these big transparent MB102 boards which have a "power rail" which includes +/- side by side in one long strip..

To make things more stable and a bit more clean looking, i put some heatshrink tubing on some wires before i soldered it.

Step 6: Oh, Mia Is Coming to Us....

Heh, sorry people but it had to. *smile*Mia our cat, she only looks still some bit like a kitten, but just recently she fought against some rude rat which probably thought our backyard may be a nice place to live...... no, not as long as mia is around.

But, in terms of curiosity, she never left her childhood.

So cute ... she always watches exactly what her servants do when not actual in duty... ;)

Well, this particular PSU had 2 pheripherial power chords where one had two 4 pin molex harddisc power connectors and one had just one 4 pin molex harddisc power connector and a smaller 4 pin floppy drive power connector.

I ripped the second cable completely in pieces and reworked them to power distribution wires.

But from the first one, i removed the second black and the yellow wire - making additional distribution wires from them - and then removed the "first" connector as seen from the PSU. I keep the second one to be able to attach a simple adapter cable for maybe 2,5" IDE disks or regular 2,5" SATA disks. (There exists merely a ton of these cables ready built out there, you should always prefer to use a ready built cable in those power connections.)

Then, i soldered 3 pins from my male pin headers to each of the prepared ends of the red and black wire, insulated them like all the others and attached the left over connectors from the removed molex connector to my nice beefy 5V 10Amps PSU which not only powers a 10 port USB hub but a raspberry pi too.

Here you can start to guess why i make this effort.. ;)

By the way, always remember to at least double check a proper insulation on your stuff.

As you can see in the pics, putting the wires for powering the USB Hub and the new wires for the breadboards, makes things go a bit tight and leave only very limited space to prevent shorts. Because i assume to move this whole mess around a lot over time, i took a bit additional care to insulate the connections directly at the PSU so that even if something bumps against the connectors, there can nothing short out the PSU. ;)

Step 8: Finally, Why You May Do This... ;)

O.k. i have some pictures left over and just wanna say something about them.

You can see 2 of my breadboard setups here. One is connected to a raspberry, now even directly connected to a beefy PSU for the Raspi and it's hub.

And the other one just contains a bunch of spare parts and a boarduino. It even needs proper 5volts power and a durable connection, like the raspi too.. ;)

At the raspi breadboard, i added a cheap dc-dc buck/step down converter to give the 3.3V rail, originally only driven by the power regulator on the raspi direct, some more amps by drawing them from the 5V rail which no longer has to go through the fuses of the raspi (wich formerly even powered the 5v rail). ;)

You can see how nicely these wires even fit the two pin config of this cheapo dc-dc converter.Ah and yes, using single wires without heat shrink tubing was way easier to connect for this special case, but eventually everything got into the place i intended, so, all is cool and fits nicely.

Now, you know why i needed to have separate color-coded wires for 5V and 3.3V,

I liked to follow the good old Microcomputer/PC/XT/AT/ATX color coding sheme, but was to lazy to cut separate orange wires from the atx power connector.

Usually, the colors for Power would be:

Black = GND/Common ground (for all power rails)

Red = +5Volts, usually atx PSU's even have several different 5v rails, but all use red.

Yellow = +12Volts. Most older harddiscs needed a lot of power (not only just to be able to start). In these days, you often see them at additional power connectors on Graphics Cards or on the mainboard for additional power for the CPU.

Orange = +3.3V. SATA connectors have them. There was no use in the old days, because of this, no connector had them. ;)

If i may need an additional 12V power source, maybe if i have all the parts for a nice full blown HVSP/HVPP capable arv/arduino MCU resetter/programmer, i will go through this again, just for the orange wires. ;)

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One easy note, at least to provide +5V & +12V (some of the older CMOS & TTL circuits) from an ATX supply, Scavenge the 4-pin mini molex connector from an old dead 3.5" floppy drive. un-solder the pins from the board, clip-off the support ears (on the solder side, they're "/_| " shaped), apply a dab of crazy glue to each pin where it fits through the plastic, and un-bend the 90-degree connection. Result, siply plug the female plug from the ATX supply to connector, and insert the solder end of the pins into 4 adjacent holes on the breadboard.

Heh ... just in the last 3 months i had eventually used your tip, to just get some little stuff on some machines working. (I even think about powerhing some desktop lighting out of my 24/7 running little desktop;)).

But anyways, yeah absolutely right. As i cleared up my 'frickelspace' (habitable electronics and computer 'lab';)) i pooled together a lot of DC/DVD readers and writers and some "good old floppy drives" .. sadly the number of 5,25" drives forbid to rip any one of them apart. But some 3,5" floppy drives which will maybe some day assigned to some floppy-instruments/musicplayers, had to give their connectors for the better. ;)

Actually and eventually, to be able to connect some external harddrives (wich need about 12v 1amp each), i will rip apart some older graphics cards and recycle their PCIe Power Connectors to get this done safely and clean. ;)